Re: make world and setuid bits

From: Crist J. Clark (cjc@FreeBSD.ORG)
Date: 03/28/02 

Date: Thu, 28 Mar 2002 12:18:50 -0800
From: "Crist J. Clark" <cjc@FreeBSD.ORG>
To: Jason Stone <jason-fbsd-security@shalott.net>

On Thu, Mar 28, 2002 at 04:40:31AM -0800, Jason Stone wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
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>
> Are there make variables that can be set to prevent "make world" from
> installing binaries as setuid? Currently, I always run something like
> "find -perms -4000 | xargs chmod u-s" after doing a make world, but this
> seems inelegant, prone to human error, and dangerous as there's a
> (potentially quite long) period in which there are still many setuid
> binaries....
>
> make options to allow the prevention of "setuid root", "all setuid",
> or "all setuid and all setgid" would be nice.

For the vast majority of users, having no setuid binaries is a really,
really bad idea from a security standpoint. It forces you to do
everything as root.

If this is a policy on some machine somewhere, I don't that there is
much of a window of vulnerability. During the installation of the new
binaries, the system would be out of normal service. The system should
be isolated from potentially hostile users. 

-- 
Crist J. Clark                     |     cjclark@alum.mit.edu
                                   |     cjclark@jhu.edu
http://people.freebsd.org/~cjc/    |     cjc@freebsd.org
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